Digital Commons Network^™

Twist-Assisted All-Antiferromagnetic Tunnel Junction In The Atomic Limit, Yullang Chen, Kartik Samanta, Naafls A. Shahed, Haojle Zhang, Chi Fang, Arthur Ernst, Evgeny Y. Tsymbal, Stuart S.P. Parkin

Nebraska Center for Materials and Nanoscience: Faculty Publications

Antiferromagnetic spintronics^1,2 shows great potential for high-density and ultrafast information devices. Magnetic tunnel junctions (MTJs), a key spintronic memory component that are typically formed from ferromagnetic materials, have seen rapid developments very recently using antiferromagnetic materials3,4. Here we demonstrate a twisting strategy for constructing all-antiferromagnetic tunnel junctions down to the atomic limit. By twisting two bilayers of CrSBr, a 2D antiferromagnet (AFM), a more than 700% nonvolatile tunnelling magnetoresistance (TMR) ratio is shown at zero field (ZF) with the entire twisted stack acting as the tunnel barrier. This is determined by twisting two CrSBr monolayers for which the TMR …

The Growth Of Ethanol In Brazil: Sugarcane, Corn, And A Few Other Things, Fabio Mattos

Cornhusker Economics

Although we can expect more ethanol produced from corn in the coming years, it is unclear whether it will keep expanding at the same pace as in recent years or how much it will contribute to total ethanol production.

One point to keep an eye on is the typical dynamics of markets. If supply and demand conditions and price movements make corn-ethanol more profitable, ethanol plants in Brazil will keep increasing their production. If it makes more economic sense to produce corn-ethanol (as it happened recently), they will use more corn to produce ethanol.

Supply and demand conditions for ethanol, …

Using Machine Learning To Determine A Functional Classifier Of Reward Responsiveness And Its Association With Adolescent Psychiatric Symptomatology, Robert James Richard Blair, Johannah Bashford-Largo, Ahria Dominguez, Matthew Dobbertin, Karina S. Blair, Sahil Bajaj

Center for Brain, Biology, and Behavior: Faculty Publications

Background. Machine learning (ML) has developed classifiers differentiating patient groups despite concerns regarding diagnostic reliability. An alternative strategy, used here, is to develop a functional classifier (hyperplane) (e.g. distinguishing the neural responses to received reward v. received punishment in typically developing (TD) adolescents) and then determine the functional integrity of the response (reward response distance from the hyperplane) in adolescents with externalizing and internalizing conditions and its associations with symptom clusters.

Methods. Two hundred and ninety nine adolescents (mean age = 15.07 ± 2.30 years, 117 females) were divided into three groups: a training sample of TD adolescents …

Enhancing Water Sustainability In North Africa: Literature Review And Synthesis Of Current Knowledge Gaps In Sudan, Osman M. A. Adam, Aaron R. Mittelstet, Derek M. Heeren, Troy E. Gilmore

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

This study delves into the critical role of groundwater in addressing global water challenges, with a focus on the Nubian Sandstone Aquifer System (NSAS) in North Africa. Groundwater constitutes a source of potable water, irrigation, and industrial use, especially in arid regions where surface water is limited. We analyzed the status of water quantity, withdrawals, recharge, and geological characteristics in the NSAS, specifically in Sudan, Egypt, Libya, and Chad. Though the NSAS is largely an untapped resource, we evaluated various scenarios to determine the quantity of cropland that can be sustainably irrigated. The NSAS is located in an arid region, …

Female Foragers Sometimes Hunt, Yet Gendered Divisions Of Labor Are Real: A Comment On Anderson Et Al. (2023), The Myth Of Man The Hunter, Vivek V. Venkataraman, Jordie Hoffman, Kyle Farquharson, Helen Elizabeth Davis, Edward H. Hagen, Raymond B. Hames, Barry S. Hewlett, Luke Glowacki, Haneul Jang, Robert Kelly, Karen Kramer, Sheina Lew-Levy, Katie Starkweather, Kristen Syme, Duncan N. E. Stibbard-Hawkes

Department of Anthropology: Faculty Publications

Gendered divisions of labor are a feature of every known contemporary hunter-gatherer (forager) society. While gender roles are certainly flexible, and prominent and well-studied cases of female hunting do exist, it is more often men who hunt. A new study (Anderson et al., 2023) surveyed ethnographically known foragers and found that women hunt in 79% of foraging societies, with big-game hunting occurring in 33%. Based on this single type of labor, which is one among dozens performed in foraging societies, the authors question the existence of gendered division of labor altogether. As a diverse group of hunter-gatherer experts, we find …

Water Current, Volume 56, No. 2, Summer 2024

Water Current Newsletter

No abstract provided.

Archaeoentomology: Arthropods And Humans, Current Works In Archaeoentomology, Paz Vigil

Department of Entomology: Distance Master of Science Projects

This paper presents a brief literature review, exploring human and insect interaction, and how such research aids the ongoing construction of the archaeological and entomological record. This field, a combined subset of both entomology and archaeology, is both complex and rich as well as young and still growing. This literature review is not meant to be an exhaustive or comprehensive exploration of this subject, but it will serve as part of a foundation for those interested in the topic or wanting to conduct further exploratory study in this field. The intent is to highlight the practical applications of Archaeoentomology, using …

Resources In Northeast Nebraska's Waste Could Power The Future, Reese Vanosdel, Emma Kurtz, Tyler Knaak

Project Energy Nebraska: Student Projects

Environmental Engagement in the Community projects, summer 2024

A poster titled Resources in Northeast Nebraska's Waste Could Power the Future for clients City of Norfolk, Nebraska (Steven Rames) and City of Wayne, Nebraska (Wes Blecke and Sandy Brown).

Advisor: David Gosselin

Evaluating A Precision Sprayer For Detecting Weeds And Spraying Herbicides In Real Time (Spot Spray) For Weed Management In Corn And Soybean, Adam Eric Leise

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Herbicide sprayers are becoming larger and more efficient in applications in crop fields. A precise and efficient herbicide application is advantageous in effective weed control. New precision sprayers were introduced in hopes of reducing the amount of herbicide applied. Greeneye Technology and John Deere have developed precision sprayers for the detection of weeds in crop fields, which come equipped with a dual tank system that allows for two different herbicides to be separated from tank to tip. The objectives of this study were to evaluate the broadleaf and grass weed control efficacy of spot spray (SS) technology when applied in …

Biostratigraphic Revision Of Esthonyx (Tillidontia, Mammalia) In The Contect Of Climate Change In The Lower Eocene Of The Bighorn Basin, Wyoming, John Colter Johnson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Esthonyx is an early Eocene tillodont found in North America, Europe, and India. The genus was named by Edward Drinker (E. D.) Cope in 1874 based on specimens from the San Jose Formation in New Mexico. Since then, several species of Esthonyx have been described from North America alone. The best record of Esthonyx comes from the central Bighorn Basin (BHB) in Wyoming, where it appears in 220 localities in a 640 m-thick stratigraphic succession. Since the last summary of Esthonyx in the BHB, several hundred new specimens have been collected and curated at the Denver Museum of Nature and …

Multi-Case Study Of Left-Flank Boundaries Within Supercells, Peyton B. Stevenson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study investigates the prevalence and significance of forward-flank convergence boundaries (FFCBs) and left-flank convergence boundaries (LFCBs) in shaping the structure and intensity of supercells, using observational data from various field projects. Unlike previous research focusing on individual cases, this study examines a diverse range of cases to provide comprehensive insights into the relationship between these boundaries and supercell characteristics such as intensity, longevity, and tornadogenesis. By analyzing high-resolution surface data, the research addresses the frequency, location, and intensity of these boundaries, and their impact on pseudo vertical vorticity, pseudo convergence, and density gradients. A total of 228 boundary identifications …

Design And Evaluation Of An Esa-Based Method Of Ensemble Subsetting For A Wofs (Warn On Forecast-Like System), Daniel J. Butler

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Forecasting severe thunderstorm environments in the southeastern United States can be challenging due to mesoscale heterogeneities such as shortwave troughs, pre-existing airmass boundaries, cold fronts aloft, low-level jets, dry air intrusions, and mesoscale lows. To combat these challenges, ensemble sensitivity analysis (ESA) may be applied to a Warn-on-Forecast (WOF)-like ensemble to improve forecasts of severe convection through ensemble weighting and subsetting. Ensemble-based weighting and subsetting uses ensemble members that most accurately represent the thunderstorm environment in areas of mesoscale heterogeneity. This study creates and evaluates the ensemble-based weighting and subsetting in four cases of severe thunderstorm occurrence. The open parameter …

Examining Dietary Disparities And Associated Factors Among Young Children Across Diverse Racial, Ethnic And Immigrant Households In Nebraska, Naveta Bhatti

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Early childhood is a crucial stage for developing eating behaviors which in turn plays a major role in determining health outcomes. Assessing children’s diet plays a crucial role in tackling the obesity epidemic. One of the ways to assess children’s dietary intake is by evaluating their dietary quality. Dietary quality refers to the overall healthfulness and nutritional value of an individual's diet, considering the combination of foods consumed over time. Research has consistently demonstrated that a high-quality diet is associated with a reduced risk of several health issues, such as all-cause mortality, cardiovascular disease incidence or mortality, cancer incidence or …

Development Of A Rule-Based Monitoring System For Autonomous Heavy Equipment Safety, Amirpooya Shirazi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Roadway construction work zones are constantly exposed to interactions among construction equipment, workers, and vehicles. Furthermore, ensuring safety in these areas is considered a challenging task due to the complexity of the environment. As shown in the rising trend of fatal accidents in roadway work zones, current OSHA regulations in construction safety are insufficient in effectively detecting unsafe situations and mitigating the risks. Furthermore, best practices, such as internal traffic control planning (ITCP), exhibit critical limitations requiring continuous monitoring of active work zones as well as adjustments to the site coordination plans due to the dynamic nature of work zone …

The Influence Of Student-Teacher Relationship Quality On Educational Outcomes For Students With Attention-Deficit/Hyperactivity Disorder, Cassidy Ann Spradlin

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The purpose of this dissertation study was to examine the associations between student-teacher closeness, student-teacher conflict, and educational outcomes (i.e., academic, social, and behavioral outcomes) for students with elevated symptoms of attention-deficit/hyperactivity disorder (ADHD). Positive student-teacher relationship quality is linked to educational success and has been found to be inversely related to adverse outcomes in the general population. Previous research has examined differences in student-teacher relationship quality for students with ADHD, but the association between student-teacher relationship quality and educational outcomes is not well understood for students with ADHD. This dissertation study examined the association between student-teacher relationship quality and …

Unmanned Aerial Vehicle (Uav)-Based High-Throughput Phenotyping For Maize Improvement, Eric T. Rodene

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Modern breeding programs rely heavily on efficiently screening large numbers of genotypes for agronomic traits, such as disease resistance, drought tolerance, and yield. Identifying the genetic loci or genes associated with these traits using GWAS or functional analyses will benefit future plant breeding efforts seeking to incorporate these traits into new crop varieties, whether through conventional breeding or gene editing techniques. Unmanned aerial vehicle (UAV)-based image data has been increasingly used for this task, as it allows entire test plots to be quickly and cost-effectively phenotyped. In my research, I have developed methods to improve the accuracy of machine learning …

Performance Fatigability And Neuromuscular Responses During And After One Set Of Forearm Flexion Muscle Actions To Failure At 30% Versus 70% One-Repetition Maximum In Men And Women, Tyler Joseph Neltner

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Previous studies have examined sex differences in performance fatigability during isometric, isokinetic and controlled dynamic constant external resistance (DCER) fatiguing tasks (FT), however, whether those sex differences remain during maximal intended velocity (MIV) DCER muscle actions remains unclear. The purpose of this study was to examine the sex-related differences in the time course of fatigue, neuromuscular responses, and coactivation from the ipsilateral and contralateral limbs during MIV DCER muscle actions to failure at low versus high relative loads, as well as performance fatigability from pre- to post-testing. Twenty-seven college-aged men (n = 14) and women (n = 13) …

Exploring Producers' Willingness To Pay For Ecosystem Services: Three Essays On Soil Health, Location Preferences, And Cover Crop Adoption, Kaouter Essakkat

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

This dissertation comprises three essays: one assessing Midwest producers' willingness-to-pay (WTP) for soil health-enhancing ecosystem services (ES), another examining the impact of policy implementation locations on WTP, and a third identifying factors influencing producers' adoption of cover crops (CC).

The first essay pioneers the understanding of agricultural producers’ valuation of soil health-associated ES amid growing concerns of soil degradation due to agricultural intensification. Using a discrete choice experiment, this study assesses producers’ WTP for a policy that incentivizes ES provision, specifically improved water quality, carbon sequestration, and enhanced crop yield. Surveying producers across Iowa, Kansas, and Nebraska, our results show …

A Collection Of Short Stories, Tryphena Lizzert Yeboah

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The short stories in this collection offer diverse and expansive realities of the human condition, particularly around the lives of women—their identities, bodies, emotions, and how they live and navigate a social order that is often constructed to dominate and undermine them. How can we complicate marginalized portrayals of women shaped by the male gaze and interrogate the patriarchal presumption of the African woman? What different approaches should be employed in capturing different aspects of her domestic and social life, how she defines and expresses autonomy, how she subverts gender norms, and her experiences of emotional and physical violence? These …

Assessment Of Foam Decontamination In Tomato Washing Process, Basim M. Alohali

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The work of the dissertation investigated the efficacy of foam-based decontamination treatments to enhance microbial safety in Roma tomatoes, specifically targeting natural microflora and Salmonella contamination. Growing concerns over foodborne illnesses linked to fresh tomatoes and the limitations of conventional decontamination techniques, such as organic matter built-up and limited microbial reduction, are addressed. The primary objectives were to characterize the physiochemical properties of foams formed using various concentrations of Tween 20 (T20) and sodium dodecyl sulfate (SDS) with and without the addition of sodium hypochlorite (NaOCl) and peracetic acid (PAA), compare the efficacy of foam and traditional dump tank (DT) …

Estranged Temporality: How Time Tells Stories In Science Fiction, Phillip H. Howells

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

According to Darko Suvin in his influential critical treatise, Metamorphoses of Science Fiction, estrangement in Science Fiction (SF) gives authors the ability to build worlds related to but distant from our own using specific metaphors. This dissertation takes up this term and applies it to the fulcrum of time in SF as a method of creating possible futures and imaginative pasts in order to illuminate the realities of the present. The realities of the present are congruent with the material circumstances of the past, and this can be seen in the kinds of SF worlds built by members of …

Genetically Modified Bovine Milk-Derived Small Extracellular Vesicles In Drug Delivery, Alice Kah Hui Ngu

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Small extracellular vesicles (SEVs, “exosomes”) are natural nanoparticles that can be endogenously synthesized and also obtained from dietary sources, such as bovine milk SEVs (mEVs). mEVs have been extensively studied and discovered with contributive features that potentially play a role in drug delivery and other therapeutic purposes, such as diagnostic tools. Current studies have shown that mEVs have been used preclinically to carry in targeting drugs, nucleotides, biomolecules, and labels to target metabolic diseases and cancers. Extensive studies have focused on further modifying SEVs to enhance their versatility in pharmaceutical use. In this dissertation, we exhibited one of the ways …

Laser 3d Printing Of Diamond-Based Composite Materials For Thermal Management Applications, Nada Kraiem

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

With the trend towards miniaturization of electrical equipment and the constant increase in power density in semiconductor devices, efficient heat management has become a major concern for researchers. Indeed, this technological evolution imposes increasingly strict constraints in terms of thermal dissipation, necessitating innovative solutions to ensure better durability and reliability of components. In this context, the use of composite materials offering high thermal conductivity (TC) and low coefficient of thermal expansion (CTE) compared to pure metals has become essential to address overheating issues in electronic components.

The utilization of advanced materials such as diamond (D), with exceptional TC and hardness …

Advancements In Microscale Tensile Testing: A Novel Device For The High Throughput Analysis Of Two-Photon Polymerized Microfibers In Liquid, Grayson D. Minnick

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Two-photon polymerization (TPP) enables the 3D fabrication of micro- and nanostructures from biocompatible materials with high resolutions, reaching into the realm of hundreds of nanometers. Such capabilities are crucial for advancing applications in fields like mechanobiology. As microscale technologies evolve, the precise characterization of material properties becomes increasingly essential. This is especially true for TPP-printed microstructures serving as scaffolds for 3D cell culture and intended for studying the mechanics of tissues. Despite the importance, traditional micro-scale tensile testing methods typically lack scalability and fail to replicate relevant environmental conditions. This dissertation introduces a new device that is specifically designed to …

Influence Of The Work Environment On Workplace Learning Of Undergraduate Engineering Interns, Yashin Brijmohan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Internships are an impactful form of workplace learning that helps undergraduate engineering students acquire and enhance competencies to improve their employability. However, the nuances about what makes an internship successful are not well understood. Furthermore, learning during engineering internships has not been thoroughly researched. Previous literature has mostly focused on internship outcomes, and there is little discussion on how to improve internship experiences to achieve the expected outcomes. Thus, this qualitative study explored the workplace learning environment of internships and how engineering undergraduate students engaged with workplace learning. The study has produced a comprehensive framework that illustrates important factors in …

Risk Factors For Online And In-Person Stalking, Intrusive Harassment, And Violence Within A Community Sample, Elisha J. C. Chan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Stalking and intrusive harassment (SIH) and stalking violence are prevalent and serious public health concerns associated with significant physical, psychological, financial, and social consequences. The growing proliferation of technology and the internet has only exacerbated the problem as SIH behaviors can be easily perpetrated via electronic means. Given its prevalence and negative impact, it is imperative to investigate the risk factors for online and in-person SIH and stalking violence to better predict and mitigate its detrimental effects. The current study therefore aimed to 1) examine the descriptive characteristics associated with online and in-person SIH and stalking violence; and 2) identify …

Population Demography, Occupancy, And Connectivity Of Invasive Bigheaded Carp In The Platte River, Nebraska And Its Tributaries, Blake W. Logan

School of Natural Resources: Dissertations, Theses, and Student Research

Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis, collectively referred to as bigheaded carp, are invasive species in the United States of America that have expanded their range throughout the Missouri River basin in the last three decades. It may be desirable to develop management plans directed at the monitoring, control, or removal of bigheaded carp within the Missouri River basin. However, a knowledge gap exists regarding bigheaded carp ecology in Missouri River tributaries, which may be important for the development of management plans. As such, this study characterized bigheaded carp population demographics, occupancy, and connectivity in …

Virtual Fencing In Livestock Management: Effects On Beef Cattle Stress And Enhancing Wildlife Conservation, Kaitlyn E. Dozler

School of Natural Resources: Dissertations, Theses, and Student Research

I examined the effects of virtual fencing on beef cattle stress and how implementing the technology can aid wildlife habitat conservation at the University of Nebraska Gudmundsen Sandhills laboratory (GSL) near Whitman, NE. First, I examined how virtual fencing influences acute heart rate changes in beef cattle fitted with the virtual fencing collars. No significant difference in the average heart rate of a cow (P > 0.05) was observed between the 30 min control and virtual fenced periods for both trial dates. Second, I examined the influence of topography on wildlife species richness and presence at GSL using wildlife camera …

Spatial Ecology Of Mountain Lions Throughout Their Distribution In California, Kyle D. Dougherty

School of Natural Resources: Dissertations, Theses, and Student Research

Mountain lions (Puma concolor) have been studied extensively throughout their wide geographic distribution in the Western Hemisphere, but most research has been conducted at relatively small spatial scales. We used GPS telemetry data contributed by researchers in 16 study areas throughout California to advance understanding of mountain lion spatial ecology. First, we investigated multi-scale resource selection of mountain lions relative to spatially varying risk of intentional human-caused mortality associated with livestock depredation management. We show that individuals that proactively avoided mortality risk when selecting home ranges were able to relax their avoidance of risk when making resource selection …

Hybridization Between The Rare Gray-Headed Chickadee And The Abundant Boreal Chickadee In The Midst Of Shifting Climate, Matthew R. Armstrong

School of Natural Resources: Dissertations, Theses, and Student Research

As species respond to changing climate, distributions and abundances may shift and alter species interactions. Hybridization, a relatively widespread phenomenon becoming more common with climate change, can have beneficial and detrimental effects on population growth rates and genetic integrity. Beneficial effects due to the introduction of advantageous alleles and increased genetic diversity may result from hybridization. Species may also accrue fitness costs associated with changing climates if mismatches occur between environmental variables and phenotypes. The gray-headed chickadee, Poecile cinctus lathami, is an extremely rare songbird that has experienced marked declines in recent decades within its restricted distribution in Alaska …